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Adaptive middleware is essential for developing distributed systems in several applications domains. The design and implementation of this kind of middleware, however, it is still a challenge due to general adaptation issues, such as When to adapt? Where to include the adaptation code? What to adapt?, and How to guarantee safe adaptations?. Current solutions commonly face these challenges at the implementation level and do not focus on the safety aspects of the adaptation. This paper proposes a holistic solution implemented in Go programming language for developing adaptive middleware centred on the adoption of software architecture principles combined with lightweight use of formalisms. Software architecture concepts work as an enabling approach for structuring and adapting the middleware. Meanwhile, the formalisation helps in providing some guarantees before and during the middleware execution. The proposed solution is evaluated by implementing an adaptive middleware and comparing its performance against existing middleware systems. As shown in the experimental evaluation, the proposed solution enables us to design and implement safe adaptive middleware systems without compromising their performance.

Background:Cadmium (Cd), which is a deadly heavy metal of work-related and environmental concern, has been recognized as a substance that is teratogenic and carcinogenic for humans. Therefore, the need to develop low-cost adsorbents to remove heavy metals from aqueous solution has greatly increased. Adsorbents such as Pantoea agglomerans biomass have been used.Aims:We investigated the biotechnological potential of Pantoea agglomerans for the biosorption of cadmium from aqueous solution.Patients and Methods: Pantoea agglomerans UCP1320 isolated from the effluent of a laundry industry was used to remove cadmium from aqueous solutions. Two approaches were compared using active or thermally inactivated biomass. Three different cadmium concentrations of 1, 10 and 100 ppm were used under constant stirring at temperatures of 25°C and 35°C as was pH of 3.0, 5.0 and 7.0. Variable incubation times of 1, 6, and 24h were also studied.Results:The results showed that the temperature did not influence the uptake of metal by living cells nor by inactive bacterial biomass. However, increasing the pH had a positive effect on removing intermediate concentrations of cadmium. Low concentrations of cadmium were completely removed by both live and inactive biomass.Conclusion: Pantoea agglomerans biomass was shown to have a promising performance for the biotechnological removal of cadmium which had been dissolved in aqueous solution.

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The increasing levels of carbon dioxide in the atmosphere, due to the consumption of fossil fuels, is the main cause of man-made greenhouse effect, thus, global warming and all sort problems associated to it. To solve those questions, researchers from different countries are developing new and more sustainable technologies and products. Among these techniques, the production of biofuels using new sources is relevant. In Brazil, ethanol obtained from sugarcane it is the most produced and used biofuel by local population. To produce enough ethanol to meet the Brazilian's demand, large crop areas are required, reducing the available space for growing food crops. An option to conventional raw materials is the employment of microalgae such as Chlorella vulgaris, that can remove and assimilate large amounts of CO2 from atmosphere, producing a highstarch biomass, which can be used to produce ethanol. In addition, other possible application of the microalgae is as biological catalyst Photosynthetic Fuel Cell (PFC) system in the cathode of a microbial fuel cell, designed to produce clean energy. In this paper, the microalgae Chlorella vulgaris was applied in an electrochemical system to generate electricity, with maximum value of Vmax 244mV.cm -2 . C. vulgaris It's also an efficient carbon sink, absorbing 3.5 mg.L -1 CO2 after 10 days of growing. The biomass composed by 40% starch, which shows potential use of these microalgae to produce clean energy and biofuels.